ARS | Publication request: First report of bacterial blight of crucifers caused by Pseudomonas cannabina pv. alisalensis in Australia.

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 3, 2011
Publication Date: August 1, 2011
Citation: Bull, C.T., Rubio, I. 2011. First report of bacterial blight of crucifers caused by Pseudomonas cannabina pv. alisalensis in Australia. Plant Disease. 95(8)1027.

Interpretive Summary: Crucifer production represents a 370 million dollar industry in Monterey County California and helps growers supply healthy green vegetables to US markets. Plant pathogens limit the supply of crucifers to consumers and profits of producers. Prior to this research a bacterial pathogen Pseudomonas cannabina pv. alisalensis had only been reported from crucifer production in the U.S. In this study we demonstrate that this pathogen was also isolated from crucifers grown in Australia indicating that the pathogen is widely distributed. This information will demonstrate the need for management practices for this pathogen world-wide.

Technical Abstract: Pseudomonas cannabina pv. alisalensis is a severe pathogen of crucifers across the U.S. Strains isolated from diseased white mustard (Brassica hirta), Brassica nigra (black mustard) and rape (Brassica napus var. napus) in Australia were reported to be similar to a pathogen recently transferred to P. cannabina pv. alisalensis. We compared three strains previously identified as P. syringae pv. maculicola to the pathotypes and additional strains of P. cannabina pv. alisalensis and P. syringae pv. maculicola. We demonstrated that the pathogens from Australia had identical host ranges and were genotypically identical or similar to P. cannabina pv. alisalensis. Thus, it was concluded that these strains from Australian crucifers were misidentified and are P. cannabina pv. alisalensis. This research expands the geographic range of P. cannabina pv. alisalensis to include Australia in addition to the U.S. and expands the hosts from which this pathogen has been isolated.